82 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 95 
related. Many of these genera are monotypic, that is, they consist of 
but a single species, which, in turn, is split up into many subspecies, 
which differ very slightly among themselves. 
It seems plausible that many genera that at one time may have con- 
tained numerous species have now been reduced to but a few or a single 
species, more persistent than the others and less plastic. Undoubtedly 
the avian family Tinamidae is very old and probably was much 
larger in some prehistoric age than it is today, only certain types hav- 
ing persisted, so that in this way many intermediate species and even 
genera have disappeared. 
_ Another fact that stands out very forcibly is that some genera of 
Mallophaga are restricted to certain genera of hosts. Most conspicu- 
ous in this respect is the group infesting the tinamous whose habitat is 
the grasslands of southern South America and the high altitudes of the 
Andes. These are the genera Tinamotis, Nothoprocta, Nothura, and 
Ehynchotus. It is only natural that in the tinamous, which harbor 
such a large number of highly diversified and specialized genera of 
Mallophaga, the two distinct divisions of the host family should have 
strikingly different types of mallophagan parasites, and a glance at the 
host list bears out this fact. Only two genera of Mallophaga, Strongy- 
locotes and Heptapsogaster, have so far been recorded from both 
groups of the tinamous, but I am not at all convinced that any of the 
species concerned are properly allocated generically. Strongylocotes 
lapogonus is a very aberrant type and might well be separated from 
the rest of the genus, while Heptapsogaster dilatatus (Piaget) is un- 
doubtedly a Rhyncothura, although previously placed by me in Hep- 
tapsogaster. As for Heptapsogaster tesselatus, from Nothoprocta, I 
was doubtful about its allocation in 1936, and said so at the time, and 
am more so at present, but I am not yet prepared to place it in 
Rhyncothura. 
Miss Clay (1937, p. 140) has described Heptapsogaster testudo from 
Nothura maculosa peruviana, but its allocation in Heptapsogaster is 
clearly an error, since it is a typical Rhyncothura, a genus confined to 
Rhynchotus, Nothoprocta, Nothura, and Tinamotis, while Heptapso- 
gaster is found almost exclusively on Crypturellus, a woodland- 
inhabiting genus of tinamous. 
The following genera of Mallophaga have thus far been taken only 
on the savanna-, or puna-, inhabiting forms of tinamous: Tinamicola, 
Rhyncothura, Docophorocotes, Cuctotocephalus, Lamprocorpus, and 
Tinamotaecola. ‘The only species of Amblycera certainly known to 
infest the tinamous have been taken on two genera of this group of 
hosts—Menacanthus arctifasciatus (Piaget) on Rhynchotus and 
M. nothoproctae, new species, on Nothoprocta. 
‘ 
